Castle Biosciences, Inc.

CSTLNASDAQHealthcare● Active

$20.28

$-0.73(-3.47%)

Market Cap$615091427

P/E Ratio—

52W High$44.28

52W Low$14.59

Avg Volume383K

Open$20.94

Beta1.02

Employees Ownership Insider Trades

Castle Biosciences, Inc. (CSTL) Number of Employees – History & Annual Headcount

Annual SEC headcount, year-over-year change, and per-employee efficiency — chart and full history below.

SEC EDGAR · FMP · CSTL · as of Feb 26, 2026

Latest filing snapshot

883

+122+16.03%vs prior year

Castle Biosciences, Inc. (CSTL) employee data is sourced from the annual SEC 10-K filing. As of 2025, full-time employees only. Global consolidated headcount. View SEC filing ↗

SEC 10-K·Period end: 2025-12-31·Full-time · Global

Total Employees

883

Change (1Y)

+122

Growth % (1Y)

+16.03%

Revenue / Employee

$389.8K

Net Income / Employee

$-27.4K

Market Cap

$610M

CSTL Employee Count

2019 – 2025 · Annual · SEC filing

Source: SEC annual filings · Hover bar to view year data · Click to view original filing

Employees History

Filing Date	Period End	Employees	Change (1Y)	Growth (1Y)
2026-02-26	2025-12-31	883	+122	+16.03%
2025-02-27	2024-12-31	761	+151	+24.75%
2024-02-28	2023-12-31	610	+67	+12.34%
2023-02-28	2022-12-31	543	+198	+57.39%
2022-02-28	2021-12-31	345	+144	+71.64%
2021-03-11	2020-12-31	201	+66	+48.89%
2020-03-10	2019-12-31	135	—	—

▸ Source: SEC Annual Reports (Form 10-K / 20-F). Employee counts as of fiscal year end. Click the ↗ icon at the end of a row to open the original SEC filing in a new tab.

Related Companies — Employee Count

Medical - Diagnostics & Research

#SymbolCompanyEmployeesMkt Cap

AMN Healthcare Services, Inc.

Fulgent Genetics, Inc.

1,313$527M #5

CSTL

Castle Biosciences, Inc.YOU

Source: /stock-peers + /profile.fullTimeEmployees · Click row → /employees · Sorted by headcount · CSTL peer comparison

About CSTL employees

CSTL Employees · Headcount

Castle Biosciences, Inc. (CSTL) employee data is sourced from the annual SEC 10-K filing. As of 2025, Castle Biosciences, Inc. had 883 full-time employees globally. Full-time employees only. Global consolidated headcount.

Castle Biosciences, Inc. employs 883 full-time employees as of the latest filing within the Medical - Diagnostics & Research industry. Revenue per employee stands at $389,840, reflecting the company's operational efficiency.

Castle Biosciences, Inc.'s workforce increased by 122 (16.03%) in 2025 compared to the prior fiscal year. The historical trend reflects the company's expansion and contraction cycles.

Castle Biosciences, Inc.'s revenue per employee of $389,840 positions it among the notable performers in the Medical - Diagnostics & Research sector for operational efficiency.

Revenue Financial statements Net income SEC filings Price history Forecast & ratings Ownership Earnings

Frequently Asked Questions

CSTL Employees · 5 questions

As of the latest SEC 10-K filing (2025), Castle Biosciences, Inc. had 883 full-time employees globally. This figure is sourced from the company's mandatory annual disclosure to the SEC.

Castle Biosciences, Inc. employee counthow many employees does Castle Biosciences, Inc. haveCSTL total employees 2025

▸ Data source: FMP /historical-employee-count · SEC EDGAR annual filings · As reported · Global consolidated headcount · As of 2026-02-26